1. Field of the Invention
The invention relates to apparatus for making chemical solutions of specified molarity, normality, molality or weight percentage corrected for water of hydration in which the volume of the combined solution may be unknown or estimated.
2. Description of the Prior Art
In chemistry, chemical engineering, manufacturing, qualitative and quantitative analysis and other diverse fields, it is often necessary to make and use chemical solutions of predetermined molarity, normality, molality and weight percentage corrected for water of hydration. The definition of molar, normal and molal and weight percent composition solutions may be found in chemistry texts or handbooks.
Molar, normal and molal solutions are conventionally made by either mixing a standard solution of known higher concentration than the concentration which is wanted and diluting the solution with solvent to lower it to the desired concentration or mixing the required amount of solute and solvent directly to produce the desired concentration. In either method, the definition of the type of solution is employed to calculate the required amount of solute and solvent necessary to make desired concentration of solution; the appropriate amounts of solvent and solute are measured; and the desired solution is made by mixing the solvent and solute.
A weight percentage solution is conventionally made by calculating the weight of solute and solvent necessary to achieve the desired ratio of solute to solute plus solvent in accordance with the definition of a weight percentage solution. Weight percentage solutions should be corrected for water of hydration of the solute in accordance with known methods.
The making of solutions of the foreging types in specified concentrations is time consuming and expensive especially where it is necessary to mix a large number of solutions using different solutes or a large number of solutions from the same solute of different concentration such as to perform a series of tests.